Several designs have been proposed to allow the mounting of a roof rack to a vehicle roof. One such design, in the previously mentioned U.S. Pat. No. 4,410,211 to Kloppe discloses a support bracket having an outwardly extending loop, which is mounted on the roof return of a vehicle roof by screws inserted through the roof return and into a backing plate which is permanently mounted inside the vehicle roof return. A leg of a roof rack is inserted into the loop of the support bracket and a hooked element on the leg engages and presses outwardly against the bracket loop. The disadvantage of the Kloppe design is that the backing plate must be mounted inside the vehicle roof while the vehicle is being manufactured, and is therefore unsuitable for aftermarket use. In addition, the outward force of the hook element when tightened onto the bracket would be likely to unseat a bracket plate which was not securely mounted using a backing plate.
Another roof rack design which has been adapted for vehicles having concealed drip moldings is U.S. Pat. No. 4,627,559 to Andersson for a Roof Rack for A Vehicle. Andersson discloses a roof rack support system in which holes are drilled into the roof return on each side of a vehicle with a bushing fitted into each hole. The foot of each end of a roof rack has two inwardly directed pins which fit into these holes. The feet are clamped against the vehicle by the action of a turnbuckle mounted in the center of a telescoping beam.
The disadvantage of this design is that the use of holes drilled into sheet metal, even with the disclosed bushings, provides an insecure attachment for the feet of the roof rack. The constant insertion and removal of the pins through the sheet metal of the roof return holes associated with mounting and dismounting the rack will have a tendency to widen the holes, and loosen the bushings, until the holes are to large to retain the pins. A related problem is that a heavy load on the roof rack will tend to distort the sheet metal of the roof return, causing the holes to widen, and damaging to the vehicle by allowing water to leak into the body or shell of the vehicle.
In addition, the holes of the Andersson design must be precisely located and drilled so that the pins fit into them.
The prior art thus has not provided a roof rack mounting system which is easily installed as an aftermarket addition, and which provides the strength and security of a factory installed mounting with a backing plate.